Mechanism for forming loop stitch



April 20, 1954 F 1, PETERS 2,675,771

MECHANISM FOR FORMING LOOP STITCHING IN CONVEYER BELTING COMPOSED OF TEXTILE FABRIC Filed Nov. 21, 1951 2 Sheets-Sheet l April 2o, 1954 RMT J PETERS 2,675,771

` MECHANISM FOR Fo NG'LooP sTIT NG 1N coNVEYER l BELTING CoMPosED 0F TEXT FABRIC Filed Nov. 21, 1951 2 Sheets-Sheet 2 775.9.' ,Fig-110. E98/ l i nventor 48 Fredenckliefefs, Mm,

(l v attorney Patented Apr. 20, 1954 MECHANISM FOR FORMING LOOP STITCH- ING IN CONVEYER BELTING COMPOSED F TEXTILE FABRIC Frederick J. Peters, Grand Island, N. Y., assignor to Globe Woven Belting Company, Inc., Buffalo, N. Y., a corporation of New York Application November 21, 1951, Serial No. 257,574

4 Claims.

In the copending application for patent of Martin J. Wagner, Serial No- 257,631, there is disclosed and claimed a conveyor belt of the type which is composed of textile fabric encased in a cured coating derived from a latex solution. This belt is characterized by loops of thread of suitable gage which are integrated with the body of textile fabric and project beyond a face thereof. These loops are of substantially uniform dimensions and are flattened in a common plane and caused to adhere to the face of the fabric from which they project. The coating is continuous and completely covers both the fabric and the flattened loops whereby the loops will present a series of flat-topped pads which are in raised relation to the fabric and provide the supporting surface of the belt. As pointed out in that application the loops are preferably provided as parts of lines of stitching in which their di.

mensions and their substantial uniformity of dimensions are controlled. So far as I am aware this stitching, as characterized by the controlled loops, is novel; and for the purposes of this speciflcation may be called loop stitching.

This invention relates to improvements in loop stitching mechanism, that is to say mechanism which eiects a stitching operation and forms the controlled loops of the character and for the purpose above described.

The principal object of the invention is to provide a loop stitching mechanism of simple mechanical character which may be substituted in a sewing machine of conventional construction for the usual oscillatory bobbin carrier used in connection with the lock stitching by which the plies of stitched canvas belting are sewed together and which may be operated by the mechanism employed for the operation of the bobbin carrier.

The conventional sewing machine for the lock stitching includes a pair of needles which are spaced an inch apart and operate in unison, each needle being associated with a bobbin carrier. In the lock stitching the belting is initially fed through the machine with the result of two parallel lines of lock stitching spaced by an inch. The belting is then shifted laterally through a quarter of an inch and again fed through the machine, the operation being repeated until all the lines of lock stitching are formed at quarter inch intervals.

In the special loop stitching the two needles of the conventional sewing machine may be advantageously retained and the sequence of feeding the belting through the machine to form the lines of loop stitching is the same.

The present mechanism, generally speaking, is characterized by the combination of an oscillatory1 loop forming element of novel form and operational characteristics, a relatively stationary lcop holding element in association and cooperation with the loop forming element, and a plate having an opening of novel form for immediate cooperation with the loop holding element and with the loops in connection with their formation and the feed movement of the belting through the machine.

In the accompanying drawings:

Figure l is a diagrammatic side elevation of a loop stitching mechanism with the belt in section and with the loop holding element engaged with two loops formed by previous operations,

Figure 2 is a similar view showing the starting position of the loop forming element in connection with the formation of a third loop.

Figure 3 is a similar view showing the loop forming element approximately midway in the course of its movement for the formation 'of a third loop.

Figure 4 is a similar view with the loop forming element in the same position in which it is shown in Figure 1, namely at the completion of its operation in which the loop have been released for engagement by the loop holding element, this figure however showing the loop holding element as engaged with three loops, the other two loops with which it is engaged being shown in Figure l.

Figure 5 is a view on an enlarged scale showing a needle in horizontal section and the terminal finger of the loop forming element in plan view and at the inception of its engagement with the thread which has been pushed through and below the belting by the needle.

Figure 6 is a sectional view of the sewing machine. this view being taken in the direction of the line of the travel of the belt and showing a loop stitching mechanism in side elevation, with its parts inthe relation shown in Figure 4.

Figure 7 is a sectional view of the sewing machine in a plane at a right angle to the direction of travel of the belt and showing the loop stitching mechanisms in front elevation and the needles in their raised positions.

Figure 8 is a diagrammatic front elevation showing the loop stitching mechanism with the loop forming elements in their starting positions and the needles in their lowered positions.

Figure 9 is a cross sectional view of the loop stitching mechanisms as mounted in the sewing machine.

Figure 10 is a partial plan view of the plate which cooperates with the loop holding element of the loop stitching mechanism.

Figure 11 is a fragmentary cross sectional view of the belting to which the loop stitching has been applied, this view being taken on the line II-II of Figure 6 but with the belting reversed for the ,purpose .of .processing as .disclosed in said Wagner application.

Figure 12 is a fragmentary longitudinal secreceives the loop from the loop fomiing element I4, it being understood that the loops are movable from the rear end of the nger to the pointed free end from which rthey are withdrawn. The opening IB has front and rear end walls which are alined generally in the direction of the movetional view of the belting to which the loop stitch- `;19 ,ment, of the belting fabric through the sewing has beenapplied, this -yiew being taken on the line I2--I2 of Figure lil.

Figure 13 is a partial rear elevation of the loop forming mechanism and assumes that the loop forming element is in the position shown in broken lines in Figure 4, the'belting being shown in cross section.

Belts in accordance with the invention of said Martin J. Wagner are characterized by loops I of thread or yarn of suitable gage which project beyond the load bearing face C and are provided by lines of special loop stitching E which are produced by the mechanism of the present in vention.

In the manufacture of the belting theloops I originally project in normal relation from the face C.

The special loop stitching E has the general characteristics of the well known fair stitching by which -theouter sole of a shoe is bonded to the welt, differing, however, in the feature of the controlled Yloops which are of substantially uniform dimensions-.Each "line of loop stitching follows afpath which Vinvolves straight alined 'threadporrbibns 3 adjoining the face D of the belting, parallel adjoining thread portions 4 and 5 extending through "the fabric -of the belting in :normal relationtd 'adiacent thread portions 3 at adjacentendsihereoand the loops I connecting the opposite'edsfofthe 'thread portions 4 and 5. Figures'l and@ 'show 'the' two needles N of the 'conventolialsev'viiigirnachine and the two similar loop 'stitchingmechanisms one for each needle, the duplication of the needles and the loop stitching mechanisminthefsfame machine being sufficientlyixidicatednlii'gure dby a bracket. `It

of cursefbeuriderstoothat the description ofa vsingleloop"stitching mechanism will be applicableto both'pf the mechanisms shown in liigures'andil.` f`

The loop stitching mechanism comprises a relatively'stationary loop holding element i3, an oscillatory loop forming element I4 and a horizontal'plate I5 which provides a part of the supporting surface for the belt and is formed between its upper and lower faces with an opening I5 of novel form. 'The opening I5 provides for the operation of the needle and also accommodates a horizontal tapering pointed finger I'I at the upper end of the loop holding element I3 and guides each loop in its movement away from the finger.- vlI he finger l1 extends in the direction of the feed movement of the belting A and overhangs the'loop forming element I4 which is pivotally connected at a point coincident with its axis of oscillation to the lower end of the loop holding element I3. The nger I'I extends in the direction of the movement of the belting fabric through the sewing machine. Its free end may be considered its forward end and is the end from which the loops are successively released as the belting fabric is moved step-by-step through the sewing machine in the stitch forming operation. The opposite or rear end of the finger I7 is connected to the loop holding eleing machine and which are respectively ad- .jacent the ends of the finger I'i and thereby cooperate with the finger to hold the loop holding element I3 relatively stationary during the oscillationof the loop forxningelernent I.

'l'.he .loop forming element IE is mounted and operated similarly to the bobbin carrier for which it -is substituted, Accordingly it has a circularly curved bearing face I8 which conformably engages the inner curved face of a split bearing ring di which is carried by a vertically positioned supporting frame 3i? of interrupted annular out line with its confronting ends in spaced relation to provide a clearance 4I Y(Figure 6) The frame d0 is vprovided at its opposite sides with coplanar outwardly projecting lugs #i2 which have supporting engagement with angle pieces 53 secured to a stationary frame part 54 of the sewing machine.

The loop holding element I3 is in the form of an upright arm which at its lower end (Figure 9) is provided with a laterally projecting stud I9 of circular cross section. The stud 9 is coincident with the horizontal axis about which the vertically positioned vloop forming element Iii oscillates and is somewhat loosely fitted in a transverse opening 26 in the element I the loose t enabling the free oscillation of the loop forming element relatively to the loop holding element I3. The stud I9 is formed with an axial threaded recess 2| for a screw 22 by which the assembly of the elements I3 and I is maintained. The opening 29 has an enlargement 23 beyond the stud I9 to accommodate the head of the screw 22 and also to provide an annular shoulder 24 as an abutment for a bearing washer 25.

The element Sli includes a body 25 which may be said to be in the form of a mutilated disc. The bearing face I8 is the peripheral edge face of the body 25 which is otherwise characterized by a cam edge face designated generally as 21. The element I4 also includes an arm 28 formed as a concentric extension of the body 23 and along which the face I8 is continued, the arm 28 having a curved inner face 2S concentric with the face I8. The cam ace 2l extends from one end of the face I8 to the inner end of the face 29 and terminates in a component 33 of a suitable degree of reverse curvature which merges the face 29. The nger I? at the upper end of the loop holding element I3 is laterally oiset as at 3l to overhang the loop forming element i5, as best shown in Figures 5 and 8, with its inner side closely adjacent the needle N when projecting beyond the lower face C (the drawings being considered) of the belting A, In the course of the operation of the element l the arm 28 moves directly below the oiset 3i. rEhe arm 28v terminates in a tapering finger 32 which extends in a direction generally opposite to the nger II and hasat its end a short lateral ez:- tension 33 terminating in a point 35,. The ex tension 33 is oiiset from that side of the finger 32 which is remote from the upright part of the loop holding element I3 and the point 34 of the extension 33 is directed laterally slightly beyond the inner face of the finger I1.

The loop forming element I4 has an operative stroke and a return stroke. During its operative stroke it first forms an extended bight W in the thread, this bight being held under tension by the usual reciprocating sewing machine thread carrier (not shown) and becoming the ultimate loop, and thereafter releases the bight which is thereupon tensioned about the linger I 1 and held by it in the form of a loop I until the next downward stroke of the needle through the belting A. The needle N is of the standard construction used in lock stitching and has on its opposite sides the usual thread channels F' and on one side the usual shallow transverse thread clearance groove G which is located above the eye. In Figure the groove G is shown at the right side of the needle and for convenience of description the thread portion in the channel F at the opposite side of the needle and which is connected to the thread carrier is designated L and the thread portion which extends across the groove G and from the upper face D (the drawings being considered) of the belting is designated R. The operative stroke of the loop forming element I4 is clockwise, the drawings being considered, and during the movement of the arm 2-3 below the 01T- set 3I the extension 33 enters the groove G as shown in Figure 5 and moves through it and its point 34 picks the thread portion R from the needle.

The needle N operates through the opening I6 which, as shown in Figure 10, is generally pearshaped. The finger Il extends toward the narrow end of the opening I6. The wall of the opening I5 at its narrow end has an upward and outward inclination as shown at 35. The needle N operates near the wider end of the opening. When the needle is within the opening i6 its location is adjacent the inner face of the finger Il at the approximate point where the ngei' projects from the offset 3|, its position being such that the extension 33 of the finger 32 which, as above noted, projects very slightly beyond the inner side of the iinger I l, may readily enter and move through the thread clearance groove G of the needle and pick up the thread portion R. In Figure 5 the nger I'I is indicated by broken lines in order to show its relation to the extension 33 during its movement through the groove G of the needle. Since the extension 33 is laterally oiset at the end of the finger 32 it will be located beyond the adjacent side face 36 of the iinger 28 to an extent such that when it passes beyond the groove G ample clearance with reference to the face tt will be left for the movement of the needle.

The general pear-shape of the opening I6 provides ample clearance for the loops through which the nger I'I projects. The tapered form of the finger II facilitates the movement of the loops along the nger in connection with the step by step feed of the belting. The inclined face 35 at the narrow end of the opening I6 serves as a guide for the loops during the feed movement of the belting whereby the loops are readily and temporarily folded between the face C of the belting and the supporting surface of the machine. When the belting has passed beyond the supporting surface the loops spring back into the positions in which they project in normal relation from the face C as shown in Figure 6.

The sequence of operations is shown in Figures 1 to 4. As shown in these figures the movement of the belting is to the left as indicated by the arrows X.

Figure 1 shows the finger II in relation to the last three previously formed loops, these being distinguished in the order of their formation as H, J and K. Figure l assumes that following the formation of the last loop K a step of movement of the belting has been completed, the loop K meantime having been moved along the iinger Il. In this figure the loop forming element I l5 is shown in the position which it has at the completion of an operative stroke and after it has released the bight W which was meantime tensioned about the finger II as the loop K; and the needle N is shown fully raised and positioned, with reference to the belting, for its next operative or downward stroke, the completion of which is shown in Figure 2.

From the position shown in Figure 1 the loop forming element i4 moves on its return stroke which is counterclockwise as is indicated by the arrow Y, Figure l being considered. At the completion of this stroke the loop forming element I4 is brought to what may be called its starting position as shown in Figure 2. In this position its arm 28 is located beyond the path of the needle and the needle has completed its downward movement through the belting.

The operative stroke of the loop forming element It proceeds from the position shown in Figure 2 and is clockwise as indicated by the arrow Z. During the initial stage of the operative stroke of the loop forming element the extension 33 of the linger 32 passes through the thread clearance groove G of the needle and the point 3a picks the thread from the needle, all as above described and as shown in detail in-Figure 5. As soon as the extension 33 passes beyond the groove G the needle returns to its elevated position, as shown in Figures 3 and 4 which also show the loop forming element in further successive stages of its operative stroke during which it has formed the tensioned bight W.

The cam face 2l has two major components 3'! and 38. The component 31 is substantially straight and is a bight forming component extending at a suitable acute angle to the inner curved face 29 of the arm 23. The reversely curved component 3i) of the cam face 27 extends between the component 31 and the face 29 and forms what may be called the throat of the angle. The component 38 is a curved component and may be called the bight releasing component. It merges with an angularlyy directed terminal component 39 which extends to the end of the bearing face I8.

When the extension 35 enters the groove G of the needle it passes above the lower end of the thread portion R with the effect of pulling the thread against the tension exercised by the thread holder and starting the bight which, as started, slides relatively along the surface 29 until it engages in the throat provided by the cam component 3o. As the movement of the element ifi continues the bight, maintained under tension the while, is elongated. In Figures 3 and e the bight is shown partially elongated and enveloping the loop forming' element i4, that is to say with its components extending along the sides of the element I@ between the belting and the throat provided by the cam component 30, the straight cam component el' being shown in Figure 3 as having a slight upward inclination to the right.

As the element i4 continues on its operative stroke the cam component 3'! is brought to a position of angularity in which the bight may be released, In Figure 4 this position is shown in broken lines and is one in `which the straight cani component 31 extends upward to the left at an angle favorable to the movement of the bight from the throat provided by the component 3Q to the bight releasing component 3B. At this time the bight has been moved across the outer face of the loop holding element I3 and is in position to envelop the finger I?. When the element I4 completes its operative stroke, as shown in full lines in Figure 4, the tension on the bight will have drawn it along the cam component 39, shortening it the while, with the result that the bight has been pulled fully clear of the element ie, and, in its ultimate shortened dimension, has been arrested and held by the shouldered rear end finger I1 which it envelope. The bight thus held is the completed loop and is shown at i in Figure 4, its position being at the point where the finger I? adjoins the offset 3l. The position of the element M shown in full lines in Figure et is the same position in which it is shown in Figure 1. Following the engagement of the newly formed loop by the iinger H the belt is advanced through a step of its feed movement whereby the icop distinguished as H is folded completely between the belting and the supporting surface ci the machine and the other loops distinguished as J, K and P are brought into the same relation as the loops H, J and KY shown in Figure l. Thereafter the element I4 moves on its return stroke as above described until it reaches its starting position shown in Figure 2 at which time the cycle of operations is repeated.

As above stated the mounting of the loop form ing element It is the same as the mounting of the bobbin carrier in a conventional sewing machine and the mechanism for its operation is also the same. These conventional parts are shown in Figures 6, 'i and 9.

The bearing face I8 of the loop forming ele ment Iii is provided upon a peripheral portion :i5 (Figure 9) which is of uniform cross sectional dimension and serves for the mounting of the element It in the frame t0. For the purpose oi such mounting the frame is formed at one side with a rabbeted recess 46 which accommodates the ring t?, this being of suitable bearing metal and being the part upon which the face it has direct engagement. The rabbet t provides a side wall and the base of a circularly curved channel in which the peripheral portion 55 is mounted, the opposite side wall of this channel being provided by a plate 48 of interrupted cir-- cular curvature arranged adjacent the outer side face of the frame 0. The plate i3 bears upon the outer face of the peripheral portion l5 of the element ifi and in addition to completing the channel in which the peripheral portion 45 is mounted serves the purpose of compensation for wear. mounting upon the Shanks of screws t9 which project laterally from the frame Iii) with their ends tapped into threaded recesses formed in the Accordingly the plate i8 has a slidablev forming element It is effected by a pair of connected oppositely projecting arms 52 and 53 which oscillate in unison and are arranged within the frame 40 `in confronting relation to the cam face 2. The components 3Q and 39 of the face 2l provide shoulders .for cooperation with the respective arms 52 and 53, the arm 52 bearing against the shoulder provided by the component 3@ `and the arm 53 bearing against the shoulder provided by the component 3G. The arms 52 and 53 are elements of a yoke-shaped part 55 (Figure 6) which is formed with a peripherally directed slot 55 in order to provide a clearance for the movement of the needle.

The extent of the part 5t from the end of one arm to the end of the other is such that when one of the arms 52 or 53 bears against its companion shoulder the other arm will be spaced from its companion shoulder. Thereby the part Eli has a delayed action eiliect in initiating the operative and return strokes of the loop forming element. Thus in Figures 2 and 3 the arm 53 is shown as bearing against the shoulder 3Q in order to push the element iii through its operative stroke, the end of the arm 52 at such time being spaced from its companion shoulder 3d and thus clearing the throat of the angle formed the face 2S and the bight forming component 3l', this clearance permitting the bight to slide rela tively beyond the end of the arm 22. When the loop forming element i4 reaches the end of its operative stroke the movement of the parted is reversed with the result that the arm 5i. is brought into engagement with the shoulder Sii and the arm 53 is moved away from the shoulder Se. it follows that upon the compietion of the operative stroke of the element ifi a momentary pause occurs before the movement of the element it on its return stroke and during this pause, the arm 53 having moved away from the shoulder 3% at the time, the bight W is drawn through the space between the end of the arm. 53 and the shoulder B and tensioned as a loop upon the iinger il, this operation being clearly shown in Figure 4 in which the part 5d is positioned with its arm 52 against the shoulder Se' in order to eiect the movement of the element ifi through its return stroke.

In connection with the duplication of the loop forming mechanism the parts 5d are integrally combined in a single member tity which bridges the space between the two Vframes il@ and is provided at its opposite sides with laterally projecting supporting arms .57 and 5S. The arms 5i and 58 terminate in sleeves 59 and 5t which are tted upon alining Vhorizontal shafts El and 62 supported in xed bearings t3 and t@ respectively, the shaft 6I being both an operating shaft and a supporting shaft and the shaft being a supporting shaft. The shaftV tl is the shaft which effects the oscillation'of the usual bobbin Y carrier and is rocked by the usual mechanism, illustration of which is deemed unnecessary.

I claim:V Y j V 'Y l. For use in a sewing machine of the type einn ployed Vin the manufacture of stitched canvas belting and for cooperation with the usual vertically movable needle in forming in convoi/er belting composed of textile fabric lines o t stitchH ing characterized by uniformly spaced loops of uniform dimensions which project in normal relation from the lower face of the belting, the needle carrying the thread under tension having the usual thread channelsV and a thread; clearance groove at one side and above its Vey'e:

a loop stitching mechanism comprising, in combination, a stationary loop holding element having a horizontal loop engaging linger which extends in the direction of the feed movement of the belting through the sewing machine and has a forward free end from which the loops are successively released as the belting fabric is moved through the sewing machine and a shouldered rear end, a plate which provides a part of the supporting surface for the belting and which is formed between its upper and lower faces with an opening in which the finger is positioned, the opening having front and rear end Walls which are alined generally in the direction. of the movement of the belting fabric through the sewing machine, the forward and rear ends of the finger being respectively adjacent the front and rear end walls of the opening, and a vertically positioned loop forming element mounted for oscillation about a horizontal axis and movable with reference to a starting position through an operative stroke and a return stroke, the loop forming element having a peripheral face, a cam face extending from an end of the peripheral face, and an extension projecting concentrically from the opposite end of the cam face and along which. the peripheral face is continued, the finger overhanging the peripheral face, they cam face having a substantially straight bight forming component which extends at an acute angle to the extension, a reversely curved terminal component extending between the bight forming component and the inner face of the extension and providing the throat of the angle formed by the bight forming component and the inner face of the extension, and a curved bight releasing component extending from the bight forming component to the peripheral face, the extension of the loop forming element being operatively movable under the finger and having a tapering terminal iinger which extends in a direction opposite to the linger of the loop holding element and at its end has a short lateral eX- tension terminating in a point, the lateral extension being movable through the thread clearance groove of the needle as lowered and the point of the lateral extension being operative at that time to pick the thread from the needle and to initiate a tensioned bight which during the operative movement of the loop forming element extends along each side thereof in enveloping relation and is maintained by and movable along the cam face, the loop forming element in its operative stroke eifeoting in succession the operations of initiating the bight and causing its relative movement to the throat of the angle formed by the bight forming component and the inner face of the extension, the elongation of the bight, the positioning of the bight forming component at an angle favorable to the release of the bight and the release of the bight consequent to its movement, as tensioned, along the bight forming component and the bight releasing component, the bight upon release from the loop forming element -being tensioned as a loop of the stitching in enveloping relation about thev loop engaging nger of the loop holding element, the loop forming element being thereupon movable through its reverse stroke to its starting po= sition in which its extension is withdrawn from under the finger of the loop holding element and is positioned in front of the needle at the completion of its downward stroke.

2. A loop stitching mechanism as set forth in claim 1 wherein the loop holding element is in the form of an lupright arm arranged at one side of the loop forming element and pivoted coaxially thereto, the arm at its upper end having a laterally oifset portion from which the finger of the loop forming element projects.

3. A loop stitching mechanism as set forth in claim 1 wherein the opening in the plate is generally pear-shaped and has a wider end and a narrower end, the iinger is directed toward the'` narrower end of the opening, and the wall of the opening at its narrower end has an upward and outward inclination, the opening being dimensioned to accommodate the loops as they are tensioned about the finger and thereafter moved along the finger in connection with the feed movement of the belting and the narrower end wall of the opening serving to initiate the folding of the loops between the face of the belting from which they project and the supporting surface of the machine.

4. A loop stitching mechanism as set forth in claim 1 wherein the loop holding element is in the form of an upright arm arranged at one side of the loop forming element and pivoted coaxially thereto, the arm at its upper end havmg a laterally offset portion from which the finger of the loop forming element projects, the opening in the plate is generally pear-shaped and has a wider end and a narrower end, the ringer is directed toward the narrower end of the opening, and the wall of the opening at its narrower end has an upward and outward inclination, the opening being dimensioned to accommodate the loops as they are tensioned about the finger and thereafter moved along the finger in connection with the feed movement of the belting and the narrower end Wall of the opening serving to initiate the folding of the loops between the face of the belting from which they project and the supporting surface of the machine.

References Cited in the le 0f this patent UNITED STATES PATENTS Number Name Date 523,361 Lichfeldt July 24, 1894 1,902,704 Kadlec Mar. 21, 1933 2,546,357 Dedmon et al Mar. 27, 1951 

